jdklan Posted January 18, 2008 Share Posted January 18, 2008 I have a 2002 Mack RD688S with an E7 engine in it. When you turn the key on, it powers up and everything seems fine, but when you go to start it, it wont start. We changed the ECU with one that works, and we checked the VECU also Quote Link to comment https://www.bigmacktrucks.com/topic/3319-e7-engine-cranks-but-no-start/ Share on other sites More sharing options...
fjh Posted January 19, 2008 Share Posted January 19, 2008 Why are you asuming its an ecu problem? DO YOU have fuel preasure? Quote Link to comment https://www.bigmacktrucks.com/topic/3319-e7-engine-cranks-but-no-start/#findComment-16371 Share on other sites More sharing options...
redman Posted January 19, 2008 Share Posted January 19, 2008 I have a 2002 Mack RD688S with an E7 engine in it. When you turn the key on, it powers up and everything seems fine, but when you go to start it, it wont start. We changed the ECU with one that works, and we checked the VECU alsotransfer pump if it has one. been there done that............... Quote Link to comment https://www.bigmacktrucks.com/topic/3319-e7-engine-cranks-but-no-start/#findComment-16392 Share on other sites More sharing options...
MACKS Posted January 20, 2008 Share Posted January 20, 2008 Is there any smoke coming out of the stack when you try to start it , if not it's not getting any fuel,if there is smoke it could be timeing. Let us know how you make out. Good Luck Quote Link to comment https://www.bigmacktrucks.com/topic/3319-e7-engine-cranks-but-no-start/#findComment-16400 Share on other sites More sharing options...
theakerstwo Posted January 20, 2008 Share Posted January 20, 2008 Is there any smoke coming out of the stack when you try to start it , if not it's not getting any fuel,if there is smoke it could be timeing. Let us know how you make out. Good Luck You are thinking the timing may have slipped or what? Quote glenn akers Link to comment https://www.bigmacktrucks.com/topic/3319-e7-engine-cranks-but-no-start/#findComment-16403 Share on other sites More sharing options...
MACKS Posted January 20, 2008 Share Posted January 20, 2008 I would make sure it's getting fuel before you do anything, it's not likley that the timing jumped but it is posible, it happend to me once when the keyway on the pump shaft broke. Is this a working truck or a running truck, did it just not start one day, if it fires up with a shot of eather than more than likley it's a fuel related problem. Crack a few inj lines on the pump and see if you have fuel when you turn it over. Quote Link to comment https://www.bigmacktrucks.com/topic/3319-e7-engine-cranks-but-no-start/#findComment-16415 Share on other sites More sharing options...
HK Trucking Posted January 20, 2008 Share Posted January 20, 2008 Did it just die suddenly on the road, or was it running OK when parked and then wouldn't start the next time you tried it?If it just died suddenly on the road, check to see if the fuel pick up tube in the tank may have cracked or broken off.About a month ago one of the IH semi tractors at work quit suddenly on the road, the fuel tank was 3/4 full, tried to get it going by filling the filter, but it would just run for a few seconds until the filter was empty again.Anyhow, we put it on the lowboy trailer and hauled it back to the shop.I hooked up a temporary fuel suction line and stuck the end of the line down into the fuel tank thru the filler neck, and the truck ran OK. This suggested that the pickup tube in the tank was defective.Pulled the tank, and on the IH tank you can unscrew the pickup tube and remove it from the tank.The pickup tube had fractured right at the very top and fallen into the tank, so even with a full fuel tank, it couldn't get fuel.I made up a new pickup tube from a piece of electrical conduit and brazed it to the pipe fitting that attaches it to the tank, installed it and reinstalled the tank and all was well.I know that most Mack tanks have the fuel pickup tube welded into the top of the tank, but if that turns out to be the problem, it's possible to use a hole saw and bore another hole in the top of the tank, weld in a female pipe fitting of the correct size and fabricate a screw in pickup tube as described earlier. That would be a lot better than buying a new $800.00 tank just because the pickup tube is bad.Note - If you're not sure of the proper safety procedures for welding on a fuel tank, have it done by someone who is. Quote "If You Can't Shift It Smoothly, You Shouldn't Be Driving It" Link to comment https://www.bigmacktrucks.com/topic/3319-e7-engine-cranks-but-no-start/#findComment-16416 Share on other sites More sharing options...
jdklan Posted January 22, 2008 Author Share Posted January 22, 2008 First of all, I would like to thank everyone that has replied to this topic. All the information recieved has been very helpfull in diagnosing this.I still havn't been able to get it to start, but I have more details on the situation.The truck was driven into the shop and it just wouldn't start the next morning. We used starting fluid, and it wouldn't start. We checked the sensors and the ECU and the wiring harnesses and we still could'nt get it to start. Then, one morning for some reason I dont know, it started right up. We used the truck for about two days with no problems. Then the driver came in the next day to take it, and it wouln't start. It has been sitting for about a week, unable to start.After reading the replies on this sight I cracked open a fuel injector line while some one else cranked the engine. Fuel was coming out of the line, and there was smoke coming out of the exhaughst. I'm thinking its a timing problem, but maybe electrical since it had the problem before, but somehow fixed itself for a couple days. Any suggestions? Quote Link to comment https://www.bigmacktrucks.com/topic/3319-e7-engine-cranks-but-no-start/#findComment-16462 Share on other sites More sharing options...
MACKS Posted January 22, 2008 Share Posted January 22, 2008 Just a thought, what kind of fuel shut off does it have electric or cable, make sure it's opening all the way.I have a 90 mack that had an electric air shut off on the pump,I had to take it off and hook up a cable shut off because sometimes it wouldent shut the fuel off and sometimes it wouldent turn it on. Quote Link to comment https://www.bigmacktrucks.com/topic/3319-e7-engine-cranks-but-no-start/#findComment-16465 Share on other sites More sharing options...
MACKS Posted February 7, 2008 Share Posted February 7, 2008 So whats up,did you get her running ? Quote Link to comment https://www.bigmacktrucks.com/topic/3319-e7-engine-cranks-but-no-start/#findComment-16839 Share on other sites More sharing options...
ciw65 Posted February 15, 2008 Share Posted February 15, 2008 We have had the same erratic problem with our quantum, a 1999 model with an EA7 470. Turns out the ECU is very sensitive to voltage drop. Anything below 11.5 volts and it gets the lack of will to work. Mack have installed a voltage warning light in the dash ( just a little red LED ). Is more of a problem on these buckets as the cab and chassis electrics are 24v and the engine is 12 volt. Check to see if you have a battery on the way out. Quote Link to comment https://www.bigmacktrucks.com/topic/3319-e7-engine-cranks-but-no-start/#findComment-17051 Share on other sites More sharing options...
Fastforword Posted December 12, 2017 Share Posted December 12, 2017 94 Mack ch. 613. V max. 400. Just stopped have fuel come on the return line to tank did the filters checked the little fuel solenoid works good. Cracked the injections lines. But no fuel there. Dealer sent me a square block with a solenoid on it for 1200. Bucks. Haven't put it on yet. Any help out there. Quote Link to comment https://www.bigmacktrucks.com/topic/3319-e7-engine-cranks-but-no-start/#findComment-387300 Share on other sites More sharing options...
HeavyHaulinMac Posted December 14, 2017 Share Posted December 14, 2017 I had a truck where I had a similar problem... turns out it was a rock in the fuel tank and would only have the problem when it moved around and blocked the fuel intake from the tank. It would be a big issue for like a week and then for like 2 months it would be fine then act up again etc. But when it wasn't obstructing the intake she ran mint... until i found that out i was going absolutely batty. Was an E7 also by the way. Thought it was electrical and fuel pump and all that hubub. Hope that helps. Sent from my SM-G892A using Tapatalk Quote Link to comment https://www.bigmacktrucks.com/topic/3319-e7-engine-cranks-but-no-start/#findComment-387430 Share on other sites More sharing options...
Richard Mcvey Posted September 17, 2018 Share Posted September 17, 2018 I have same problem with 1998 Mack e7 crank no start but no fuel too injector it has a Electric injector pump but on that not I found my starter has a really bad draw it’s pulling my 12.87 volts down to 8.6-9 volts so I have a starter order for it so I’ll see how that works Quote Link to comment https://www.bigmacktrucks.com/topic/3319-e7-engine-cranks-but-no-start/#findComment-406195 Share on other sites More sharing options...
Adam9066 Posted September 18, 2018 Share Posted September 18, 2018 We had an 05 e7 with a no start or had a rough idle before the no start happened and we discovered the fuel line going over the motor went bad so we made all new fuel lines for them. It's hard to tell those coated lines go bad and they dry rotten and the cloth covering hides it. Then the fuel pump can't pull fuel as it's on the vacume side. Quote Link to comment https://www.bigmacktrucks.com/topic/3319-e7-engine-cranks-but-no-start/#findComment-406231 Share on other sites More sharing options...
Los76 Posted September 21, 2019 Share Posted September 21, 2019 I have a 2003 mack with ami 370 that cranks but wont s, can anyone helptart unless u spray either to it ,runs only with either change out ecu fuel pump fuel line fuel filters and now I am just stuck ,have bno smoke coming out the stacks but when crack injector fuel lines fuel does come out of them Quote Link to comment https://www.bigmacktrucks.com/topic/3319-e7-engine-cranks-but-no-start/#findComment-432573 Share on other sites More sharing options...
Mack Technician Posted September 25, 2019 Share Posted September 25, 2019 On 9/21/2019 at 1:33 PM, Los76 said: I have a 2003 mack with ami 370 that cranks but wont s, can anyone helptart unless u spray either to it ,runs only with either change out ecu fuel pump fuel line fuel filters and now I am just stuck ,have bno smoke coming out the stacks but when crack injector fuel lines fuel does come out of them Did you do service work on the engine? Did you open the fuel system or did this happen spontaneously? Quote Link to comment https://www.bigmacktrucks.com/topic/3319-e7-engine-cranks-but-no-start/#findComment-432830 Share on other sites More sharing options...
Los76 Posted September 25, 2019 Share Posted September 25, 2019 I opened fuel system,i do have smoke coming out of the stacks now but still just cranks getting plenty of fuel out of the return line also,even have changed out engine harness Quote Link to comment https://www.bigmacktrucks.com/topic/3319-e7-engine-cranks-but-no-start/#findComment-432831 Share on other sites More sharing options...
Mack Technician Posted September 25, 2019 Share Posted September 25, 2019 (edited) oooo boy, stop changing those high dollar parts. reassemble your fuel system completely. You have a CCRS engine that will not bleed like a normal E7 or E-Tech systems. One by one crack the fuel lines at the spot where they enter the head. For each line your cracking you need to be simultaneously pumping the transfer pump hand primer. Let the fuel run out of them and retighten them, the whole time you are pumping, or your evil assistant will need to be pumping. After each is bled you should be making fire. For the next couple days fuel is going to weep from the head cavity the upper line runs into, don't worry about it, it's not a leak. Unfortunately, this is the most effective way to bleed these. You can have some smoke and not enough cylinders going live to fire up. Ether gets it rolling fast, but still may not force the compressible, aeriated, fuel through the nozzle. For the sake of posterity let us know if it works, thanks. Edited September 25, 2019 by Mack Technician 1 Quote Link to comment https://www.bigmacktrucks.com/topic/3319-e7-engine-cranks-but-no-start/#findComment-432832 Share on other sites More sharing options...
fjh Posted October 3, 2019 Share Posted October 3, 2019 Yup amen to that! Tech ! I have found that if you get solid fuel to at least two injectors you will be able to make it run! We have a guy at my shop refuses to bleed At the head and cranks at the starter for ever, to get them to go Drives me nuts! He claims he read some where Mack did not recommend this method ! I believe it stems back to the fuel line feasco early 2000's when they changed to the dollar store supplier !!! they would also have u change the fuel line every time they are removed! I say OF Coarse! Mack recommends a alot of stupid shit they get to sell more parts that way They can sell starters and fuel lines by the bushel with the bleed at the pump method! So get fuel to as many injector s as possible and it will start fine! 1 Quote Link to comment https://www.bigmacktrucks.com/topic/3319-e7-engine-cranks-but-no-start/#findComment-433286 Share on other sites More sharing options...
Mack Technician Posted October 3, 2019 Share Posted October 3, 2019 (edited) Mack is pretty spooky about drips of fuel anywhere near the exhaust manifold. Maybe good since they sent a bunch of AC ASETs into the atmosphere as a black vapor. Was talking to fuel shop Mike a while back. He was called to testify as an expert witness for a dealership customer who got CCRS injectors installed in a non CCRS engine. Destroyed a lot of hardware. Anyway, Mike was explaining there’s a point in the injection cycle where fuel is allowed to back-flow away from the CCRS injector. That’s what makes them such a pig to bleed, it’s not a one way street. It’s part of the dynamics that allow them to use a non-leak-off injector. Edited October 3, 2019 by Mack Technician Quote Link to comment https://www.bigmacktrucks.com/topic/3319-e7-engine-cranks-but-no-start/#findComment-433287 Share on other sites More sharing options...
Popular Post JoeH Posted October 3, 2019 Popular Post Share Posted October 3, 2019 Could you imagine trying to teach a jury the mechanics of a fuel injection so they can deliberate? Let alone an injection that allows the fuel to flow backwards into the injector? I suppose pulling your own fingernails out might be an easier task! 2 1 Quote Link to comment https://www.bigmacktrucks.com/topic/3319-e7-engine-cranks-but-no-start/#findComment-433291 Share on other sites More sharing options...
Mack Technician Posted October 3, 2019 Share Posted October 3, 2019 31 minutes ago, JoeH said: Could you imagine trying to teach a jury the mechanics of a fuel injection so they can deliberate? Let alone an injection that allows the fuel to flow backwards into the injector? I suppose pulling your own fingernails out might be an easier task! Funny, you nearly quoted him. He pulled some hair out, but wasn’t too frazzled once he was reimbursed the equivalent of three weeks pay for what took 1 day plus 6 hours of driving. 1 Quote Link to comment https://www.bigmacktrucks.com/topic/3319-e7-engine-cranks-but-no-start/#findComment-433292 Share on other sites More sharing options...
fjh Posted October 4, 2019 Share Posted October 4, 2019 21 hours ago, Mack Technician said: Funny, you nearly quoted him. He pulled some hair out, but wasn’t too frazzled once he was reimbursed the equivalent of three weeks pay for what took 1 day plus 6 hours of driving. Nice! Quote Link to comment https://www.bigmacktrucks.com/topic/3319-e7-engine-cranks-but-no-start/#findComment-433342 Share on other sites More sharing options...
Dewayne Garcia Posted December 12, 2019 Share Posted December 12, 2019 Goodmorning u all I have mack 2000 rd688s E7 I change out the harness to injectors truck wont still start just crank over I use starting fluid I'll start died out I have 0.5 volt to injectors Quote Link to comment https://www.bigmacktrucks.com/topic/3319-e7-engine-cranks-but-no-start/#findComment-437892 Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.